If i were you i just unlock my bios and set the TOLUD value to fix 2.25gb and disable the dgpu. Then you can forget about dsdt override.
After that just reinstall windows because you probably get ACPI_BIOS_ERROR if you modify your TOLUD, at least thats what happend on my N53SN.
Pin22 isolation only needs if your bios hangs at startup on every delay settings(motherboard forces #PERST instantly).
So in the end my system only needs PIN22+PCI compaction with setup1x to work with the eGPU.
Your bios modding needs the exact same steps(N53S and N55S and N550JV bioses are almost identical), so you can just do the exact same steps with your bios file, and yes i checked it before i sent you this message but only flash it with your own risk [N55SFAS_207_unlocked.rom] and i strongly recommend to do the steps yourself and not just download and yolo what i linked. For last word you will unlock bunch of new options and you can set up these new setting wrong (for example: don't disable the igp) causing black screen upon boot --> CMOS reset helps. But if you just play with the settings what you need then you are good.